Cap-lining fastener for electrical lamp-sockets.



E. H. FREEMAN.

GAP LINING FASTBNBR FOR ELECTRICAL LAMP SOCKETS.

APPLICATION FILED SEPT. 11, 1911.

1,021,243. Patented Mar.26, 1912.

EDGAR H. FREEMAN, OF TRENTON, NEW JERSEY.

GAP-LINING FASTENER FOR ELECTRICAL LAMP-SOCKETS.

Specification of Letters Patent.

Application filed September 8, 1911.

Patented Mar. 26, 1912.

Serial No. 648,314.

To all whom it may concern:

Be it known that I, EDGAR H. FREEMAN, citizen of the United States, residing at Trenton, in the county of Mercer and State of New Jersey, have invented certain new and useful Improvements in Cap-Lining Fasteners for Electrical Lamp-Sockets, of which the following is a specification.

This invention relates to the subject of casings for electrical lamp sockets, and has particularly in view an improved means for fastening in place the insulating lining for the cap of an electrical lamp socket casing, whereby the lining will have a snug fit within the cap and be securely held in such position as to thoroughly and satisfactorily secure a proper insulation of the lamp socket parts within the cap and otherwise fulfil all the requirements of the National Board of Fire Underwriters.

Heretofore various expedients have been resorted to for the purpose of securing in place what is known as the cap lining for lamp sockets, which expedients have involved fastening projections or elements of various kinds formed integral or otherwise with the sheet metal cap, or with the shell part of the casing. In some forms of lining fastenings the resiliency of the insulating lining has been depended upon to effect a locking action while in other forms of construction eflort has been made to permanently secure a rigid lining in place by suitable fastening elements.

In contradistinction to the known lining fastening means above referred to, the present invention contemplates a simple and practical lining fastening that is readily removable and replaceable, and also readily adaptable to the conventional forms of socket caps without alteration in the shape or any of the usual elements thereof. Also, the invention has in view a cap lining fastening that removably secures the lining in place while at the same time, when in locked position, holds the lining in such a manner that it is impossible for the same to become displaced while the socket is in use. Furthermore, the improved fastening device permits the use of a lining that may be held in snug registering fit upon and against the inner surface of the cap.

A stillfurther feature of the invention resides in the provision of a cap lining fastener which is simple and inexpensive to make and easily applied by unskilled workmen.

With these and other objects in view, the invention consists in certain novel combinations and arrangements of the parts as will more readily appear as the description proceeds, the novel features thereof being pointed out in the appended claims.

Though susceptible to structural modification without departing from the scope thereof, the essential features of the invention are exemplified in the accompanying drawings, in which:

Figure 1 is an enlarged sectional View of the casing cap of an electrical lamp socket having its insulating lining held in place by the improved fastening means contemplated by the present invention; Fig. 2 is a cross sectional View on the line 22 of Fig. 1; and Fig. 3 is a detail plan view of the spring locking ring.

Like references designate corresponding parts in the several views of the drawings.

Referring to the embodiment of the invention suggested in the accompanying drawings, the numeral 1 designates the cap part of the metallic casing or shell for an electrical lamp socket of any conventional form or design, and adapted to be lined upon its inner surface with a lining or washer 2 of suitable insulating material. This lining or washer 2 is preferably of the dished type and of a size to register snugly within the correspondingly shaped cap, and it is proposed by the present invention to tightly and securely hold the lining in place within the cap while at the same time permitting of its ready removal and replace ment whenever desired. This is accomplished by the employment of a spring split locking ring 3.

The locking ring 3 is preferably made of light spring wire of small diameter so as to preferably offer no projection beyond the inner lower edge of the lining 2. Said ring is also preferably so constructed as to be formed with a number of outwardly extending offsets 4 which form catch projections that are intended to snap into engagement with, so as to lie within, keeper slots or openings 4 which are punched through the sheet metal body of the cap 1. The spring split locking ring 3 may, therefore, be said to be of a corrugated construction, though, for purposes of illustration, the offsets or bends 4 are shown as being spaced quite a distance apart with the keeper slots or openings 5 correspondingly spaced.

From the construction described, it will be obvious that when the lining 2 is positioned within the cap, it is only necessary to spring the ring 3 into its locked position beneath and against the lower edge of the lining with the result of securely and tightly holding the lining as well as being itself held against rotary or outward displace ment on account of the engagement of the projections 4 in the slots 5. To remove the ring from the lining, it is only necessary to insert a tool behind the split ring to press the same so as to release it from the slots 5.

I claim:

1. In a lining fastening for lamp socket caps, the combination of a cap, a lining of insulating material fitting within the cap, and a locking element having engagement with the cap at spaced points and arranged to engage beneath one edge of the lining to support the latter in position.

2. In a lining fastening for lamp socket caps, the combination of a cap, a lining of insulating material fitting Within the cap and a spring locking ring having catch engagement with the cap at a plurality of spaced points, said ring being arranged to engage beneath one edge of the lining supported in position.

3. In a lining fastening for lamp socket caps, the combination of the cap having a plurality of keeper slots in its wall, a lining of insulating material fitting within the cap and a spring locking ring arranged beneath an edge of the lining and having a plurality of catch projections for engagement in said slots.

In testimony whereof I hereunto affiX my signature in the presence of two witnesses.

EDGAR H. FREEMAN.

l/Vitnesses MARY S. CURTIS, ANNIE A. HENRY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

